12 Filter Modes

Filter modes are the preferred way to specify combinations of
filters which are used regularly and thus abbreviate Aspell’s
command line arguments.

A new filter mode is specified by a file named like the filter
new mode and prefixed by .amf (Aspell Mode File). If such a file
is accessible by the path set via filter-path option Aspell
will try to load the contained mode specification.

12.1 Aspell Mode File

The first key in the made file has be the mode key.
It is checked against the mode name part of the .amf file.
If the mode key is missing mode file will be rejected.

The same holds for the aspell key which specifies the
version(s) of Aspell which is(are) required by the filter.

If these two keys are followed by at least one magic key
Aspell will be able to select the entire mode from extension and
if required from contents of the file to spell implicitly.

The last key of the required keys is the des[c[ription]]
key. It gives a short description of the filter mode which will
displayed when type aspell help.

The rest of the file consists of the keys filter and
option to load filters are set various options.

12.1.1 Version Line

Each version line must start with aspell and be followed by a
version, optionally prefixed by a relational operator. The relation
operator can be one of ‘<’, ‘<=’, ‘=’, ‘>=’ or ’>’ for allowing Aspell
version with version number being lower, lower or equal, equal to,
greater or equal or greater than required version number,
respectfully. If the relation operator is omitted ‘=’ is assumed.

12.1.2 Magic Line

The magic line contains a description which requirements files
have to fulfill in order to implicitly activate the entire mode
at least one such line is required. Each magic line has the following
format:

MAGIC /<magic key>/<fileextention>[/<fileextention>]

The magic key consist of three ‘:’ separated fields.
The first two are byte counts the last is a regular expression.
The first byte count indicates the first byte the regular expression
will be applied to the second byte count indicates the number of
bytes to test against the regular expression.

If mode selection should only occurred on basis of the listed file
extensions the magic key should consist of the “<noregex>” special
string.

At least one <fileextention> is required per MAGIC line.
<fileextention> may not be empty and should not contain a leading ‘.’
as this is assumed implicitly.

Multiple MAGIC lines are allowed. Modes may be extended limited by additional
<label>.amf files located in –filter-path
Thus file extensions may be prefixed by ‘+’ or ‘-’ to indicate that
the entire extension has to be added ore removed from this <magic key>
if neither is specified than a ‘+’ is assumed implicitly.

12.1.3 Description Line

The required description line will be printed when typing
aspell help. Keep it as short as possible. Possible
abbreviations are des and desc.

12.1.4 Filter and Option Lines

The filter and option keys load filters and set filter
options.

The value of the filter key is equal to the value of Aspell’s
[add|rem]-filter option.

Each option line has the following format:

OPTION <option> [<value>]

The format of the <option> and <value> is the same format as
found in the Aspell configuration file.